Q. The given sentence is in active/ passive voice. Change the voice of the sentence. Select the correct option from the sentence below.
He had kept up his diet program for a month.
a. His diet program had been kept up for a month.
b. His diet program was kept up for a month.
c. His diet program had been kept for a month.
d. The doctor had kept up his diet program for a month.
No explanation is available for this question!