Which of the following statements is/are correct about the people of stone age

Q. Which of the following statements is/are correct about the people of stone age?

(a) They had to depend entirely on tools and weapons made of stone

(b) They settled down only on the slopes of the hills, in rock shelters and the hilly river valley

(c) They could not produce more than what they needed for this bare subsistence

 (d) All of the above

Ans: (d) All of the above