If ? = +, ? = -, ? = ×, and ? = ÷, what is the outcome of the expression 15 ? 5 ? 3 ? 6 ? 2?

A. 18

Choose a word similar to the group: 'happy, joyful, elated'.

B. CHEERFUL

Choose a word similar to the group: 'fast, quick, rapid'.

B. SWIFT

Choose a word similar to the group: 'diligent, industrious, hardworking'.

B. PRODUCTIVE

Choose a word similar to the group: 'ancient, old, archaic'.

C. HISTORIC