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 $\mathit{A}$ and $\mathit{R}$ are true and $\mathit{R}$ is correct explanation of the Assertion.
(b) Both $\mathit{A}$ and $\mathit{R}$ are true, but $\mathit{R}$ is not the correct explanation of the Assertion.
(c) $\mathit{A}$ is true, but $\mathit{R}$ is false.
(d) $\mathit{A}$ is false, but $\mathit{R}$ is true.