Central Board Of Secondary Education [CBSE] — Ambiguity in the instructions of board maths exam class 12

In the maths paper of class 12 academic year[protected]. The paper clearly says in the instructions of the first page that you have to do 8 question out of 10 in section-C from Q.no = 41 to 50. But the case study of set[protected] has further put a constraint on the student that he/she can only do 4 out of 5 question. Hence the pattern is disturbed as there is no such limitation in the official cbse sample paper. The board cannot just change Or deviate from the pattern given in the sample paper but in case if it does so it has to be clearly mentioned before that question as well as in the instructions.
I have even further attached the instructions of the sample paper for convenience. Thankyou.