Incomplete combustion of coal and petroleum:**
(A) increases air pollution
(B) increases efficiency of machines.
(C) reduces global warming.
(D) produce poisonous gases.
The correct option is :
(a) (A) and (B)
(b) (A) and (D)
(c) (B) and (C)
(d) (C) and (D)
For question numbers 13 and 14 , two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below :
(a) Both A and R are true and R is correct explanation of the Assertion.
(b) Both A and R are true, but R is not the correct explanation of the Assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.