The correct Active/Passive form of the given sentence is:

☀ Rajeev chose his words with care.

Explanation for other options:

☀ Rajeev had chose his words with care. This option is not grammatically correct. The correct form should be "Rajeev chose his words with care," not "Rajeev had chose his words with care." The past tense of "choose" is "chose," not "had chose."

☀ Rajeev had been chosen his words with care. This option is not grammatically correct. The correct form should be "Rajeev chose his words with care," not "Rajeev had been chosen his words with care." The passive form is "were chosen," not "had been chosen."

☀ Rajeev had chosing his words with care. This option is not grammatically correct. The correct form should be "Rajeev chose his words with care," not "Rajeev had chosing his words with care." The correct form is "chose," not "chosing."