Step 1: Understanding the Question:
This question tests knowledge of wood grain patterns.
Step 2: Detailed Explanation:
Shorea robusta (sal) is a classic example of interlocked grain.
It has a distinctive grain pattern that is interlocked.
Wavy grain (B): Not characteristic of sal.
Spiral grain (C): Not characteristic of sal.
Straight grain (D): Not characteristic of sal.
Thus, the correct answer is interlocked grain.
Step 3: Final Answer:
Thus, Shorea robusta is a best example for interlocked grain, which corresponds to option (A).
[0.5cm]