Step 1: Identify the tense and voice of the original sentence. It is written in the simple present tense and is in the active voice.
Step 2: Recall the rule for forming the passive voice in the present tense. The structure is:
is/are + past participle of the verb.
Step 3: Determine the correct form of the auxiliary verb. The subject “French” refers to the name of a language, which is treated as a singular noun. Therefore, the correct auxiliary verb to use is is.
Step 4: Among the given options, only option (A) correctly follows the present passive structure and agrees with the singular subject. Hence, it is the correct answer.