This is a business law question PLEASE I really need HELP !!! PLEASE answer ALL questions!!!! THANK YOU.

Laverne offers to sell her law books to Derrien for $500. Derrien agrees. This is known as a(n) O concurrence O agreement O promise O alliance O offer Barbara Bush promises to pay Melania Trump for her new car on Friday the fifth. Melania agrees to sell her car to Barbara. Today is Monday the first. Today, this is a(n) ---- executed contract O voidable contract (at the election of either party) O unilateral contract O bilateral contract O unilateral promise Maury and Connie have agreed verbally that Maury will buy Connie's house and horse barn next month for $250,000. This contract is ----- and ------ O executed; implied O ; illusory; implied O executory; implied O express; bilateral O ; express; executed