Could anyone please help me answer the question below?

Could anyone please help me answer the question below? I would like an explanation for each options why or why not amount to consideration under contract law as well. thanks a lot!

Which of the following do not amount to consideration under contract law?

a. $0.05 (i.e. 5 cents)

b. A promise to Tom to pick up rubbish from Jack's house

c. A promise to think about an offer

d. A expensive painting given to the Tina the week before she makes an offer to sell a valuable vase to you