Question

which of these is a challenge to social relationships as a result of nicotine and tobacco use?
yellow teeth and nails
extra taxes on cigarettes
fear of expulsion from school
penalties from buying cigarettes if underage

Explanation:

Yellow teeth and nails due to nicotine and tobacco use can be a turn - off to others, straining social relationships. Extra taxes, fear of expulsion, and underage penalties are more about legal and financial aspects rather than direct social relationship challenges.

Answer:

yellow teeth and nails