Which word from the given options is most similar in meaning to the word in capitals when used as a verb?

LOCK

When used as a verb, "blind" means to make someone unable to see or to obscure someone's vision.

"Gaze" means to look steadily and intently, often with admiration or fascination.

"Bold" means showing an ability to take risks; confident and courageous.

Therefore, the word that is most similar in meaning to the capitalised word when used as a verb is "engage", which means to participate or become involved in an activity or conversation.

The answer is option B.