Answer:
The registers that are compared are instructions 3 and 4
Step-by-step explanation:
From the question given,
Recall that we need to explain what the hazard detection unit is doing during the 5th cycle of execution and which registers are being compared.
Now,
The instructions on the 5th cycle, at the stage ID/EX and IF/ID:
The instruction values are in ID/EX : sub $t2, $t3, $t6 (instruction 3)
The instruction values are in IF/ID: sub $t3, $t1 $t5 (instruction 4)
The register $t3 is compared in the instructions 3 and 4
The hazard detection unit between instruction 4 and 5t o be compared, it need to find out the values of $t1