I'm not sure but it might be C
Traits that are passed down on an X or a Y chromosome are sex-linked traits. Most of the time males are affected by sex-linked traits because males only have one X and a Y. The Y is the chromosome that makes a man, a man.
Smog is an abiotic factor affecting a biotic factor(s).
This is because smog isn't a living organism so it is abiotic while humans are multicellular organisms so therefore, they are biotic factors.
Smog has a negative effect on many biotic factors.