Option 1 states that both Assertion (A) and Reason (R) are true and R is the correct explanation of A.

First, let`s analyze Assertion (A) which states that coniferous forests account for a greater share in the total timber production of the world. This means that coniferous forests produce a larger amount of timber compared to other types of forests.

Next, let`s look at Reason (R) which states that major areas of coniferous forests occur only in the northern hemisphere. This implies that coniferous forests are predominantly found in the northern hemisphere.

Option 2 states that both Assertion (A) and Reason (R) are true, but R is not the correct explanation of A.

In this case, although both assertions are true, Reason (R) does not provide a valid explanation for Assertion (A). The fact that major areas of coniferous forests occur only in the northern hemisphere does not directly explain why coniferous forests account for a greater share of timber production worldwide. There could be other factors such as the economic importance of timber from coniferous forests or the specific characteristics of coniferous tree species that contribute to their higher timber production.

Therefore, option 2 is the correct answer.