I think that this is a very rude response. If you don't like the person's question, feel free to not respond to it.
Additionally, I disagree with your statement. Nursing is a broad field, and I don't think it can be boiled down to "deals with the actual human body". I also think that it is important that nursing deals with "how social conditions affect people". Sure, nursing, especially acute care, is very focused on the pathophysiology of the human body, but I think understanding social conditions is paramount to any nursing role. Social determinants of health, interpersonal care, all of these things are relevant to BOTH social work and nursing.
As for OP's question: there are some nursing roles that look very similar to a social worker, particularly in community health. For example, the home care case manager role in my community is currently filled by a social worker, but could also be done by a nurse (one of several examples). Both do psychosocial assessments and help clients access the resources they need and provide supports. Since I am a nurse, not a social worker, it's a bit easier for me to explain the differences in nursing. Nursing does encompass more of a biological element to its care though. If you are in acute care, this can look very medical-based, with doing a lot of physical assessments and interventions. In other settings, even community settings you will be considering the biological aspect of things as well as the socioenvironmental ones. A mental health nurse will be assessing for biological dimensions of medications, illnesses, etc that are working along with social factors of that client's life. A social worker would not have that biological knowledge to necessarily consider those factors (although their expertise probably involves other considerations that nurses aren't meant to have).
Both are valuable careers, and if you are still in the early stage of deciding a career, I can see why both of these came to mind because they have a lot in common: they stem from wanting to help and care for other people and often involve similar assessments and interventions. You have to decide what type of work environment you think suits you best, and what your skills and strengths are. I recommend researching the different types of roles that nurses and social workers can have. Both work in a wide variety of settings and with different populations. IF you get a chance to job shadow someone in either profession, that may also help you decide where you are best suited to work. Best of luck