Question

the question. 6. How are most adjectives changed into adverbs? A. By moving their place in the sentence B. By adding –ly to the end of the word C. By adding the suffix –d or –ed D. By including an irregular verb

Answer 1

B. By adding -ly to the end of the word

Answer 2

It is:  B. By adding -ly to the end of the word

examples:
The light is too bright. .adj
The light shines brightly. .adv

His snoring is too loud. .adj
He snores too loudly. .adv

The snail is too slow. .adj
The snail moves too slowly. .adv