Option 1 states that both the assertion (A) and the reason (R) are true, and furthermore, that R is the correct explanation for A.

The assertion (A) states that in summer, a block of iron is hotter than a block of wood. This statement is generally true because iron has a higher thermal conductivity than wood, meaning it can absorb and retain heat more efficiently.

The reason (R) states that the relative density of iron is more than the relative density of wood. This statement is also generally true because iron is denser than wood.

However, R is not the correct explanation for A. While the relative density of a material can affect its ability to conduct heat, it does not directly explain why a block of iron would be hotter than a block of wood in the summer. Other factors such as thermal conductivity and insulation properties also play a role in determining the temperature difference between the two materials.

Therefore, option 2 is the correct answer, indicating that both A and R are true, but R is not the correct explanation for A.