A. He requested to his friends that they should play then
B. He proposed to his friends that they would play then.
C. He proposed to his friends that they should play then.
D. He proposed to his friends that we should play then.
Explanation: He said to his friends. "Let us play now" বাক্যের indirect speech হচ্ছে - He proposed to his friends that they should play then.
Let us থাকলে propose বসে, এই বাক্যে that এরপরে they should বসবে এবং now এর পরিবর্তে then হবে।
