My goodness, I could use some economics help right about now...?

[Nader G]

1) At his current level of output, a monopolist has an MR of $10, an MC of $6, and an economic profit of zero. If the market demand curve is downward sloping and his marginal cost curve upward sloping, the monopolist
a. is producing his profit-maximizing level of output.
b. could increase his profit by increasing his output.
c. could increase his profit by increasing his price.
d. should exit the market if he has positive fixed cost.

2) Monopolists may in the long run...?
a. earn positive economic profit.
b. be protected by barriers to entry.
c. grow wealthy at the expense of their consumers.
d. All of the above are correct.

3) A monopolist's cost curves will
a. be identical to those of a competitive firm.
b. be higher than a competitive firm's cost curves.
c.be peculiar to the individual producer since there is only one.
d.drop more steeply as output increases.