Chemistry MC question

1) What is single covalent bond?
a. a electron are shared with two atoms
b. one pair of electrons are shared between atoms
c. when one atom contributes both electrons in a bonding pair
d. It's an average of two or more lewis structures, which is different only in the position of their electrons.

2) What are the properties of Metallic Bonds?
a. conduct electricity, and outer electron aren’t attached to a single atom
b. very brittle, and cannot conduct electricity