Explanation:

- Consideration: This is a key concept in contract law, implying something of value exchanged between parties.

- Executor: The party who must perform something under the contract as promised.

- Executed: This refers to actions or performance that has been completed in accordance with the contract.

- Either (a) or (b): Suggests the consideration can be from the executor or executed.

- Both (a) and (b): Means consideration involves actions before (executor) and after (executed) the agreement.

Either (a) or (b) is correct as consideration can come from either party involved, depending on who gives and receives it. .