Answer:
1) A methyl group consists of a carbon bonded to three hydrogen atoms
Explanation:
This is the answer your teacher probably expects.
Technically, however, all three are correct.
2) A C atom is slightly more electronegative than an H atom, so a methyl group is slightly polar. The polarity is so small that we usually call the methyl group nonpolar.
3) The C atom is at the negative end of the group dipole, but the charge is so small that we usually consider it to be zero.