Consider the C struct defined below:struct data { int marks [100]; char grade; int cnumber;};struct data student;The base address of student is available in register R1. The field student. grade can be accessed efficiently using

• A. Post-increment addressing mode, (R1) +
• B. Pre-decrement addressing mode, - (R1)
• C. Register direct addressing mode. R1
• D. Index addressing mode. X (R1). Where X is an offset represented in 2’s complement 16- bit representation.