Final answer:
The PC target address when the subtraction result is 0 would be the address specified by a branch instruction such as BEQ (Branch if Equal), as this indicates the condition for branching (equality) has been met.
Step-by-step explanation:
When a subtraction result is 0, it suggests that there may be an issue with assembly language programming or computer architecture, which is why the question about the PC target address is raised. The address of the subsequent instruction that the CPU will execute is stored in the PC, which stands for Program Counter in this context. When working with conditional branch instructions, the PC might be updated in response to the outcome of a subtraction carried out in order to satisfy a condition, such as a value comparison. In general, the two values are equal and the branching condition has been satisfied if the subtraction result is 0. When using the BEQ (Branch if Equal) instruction, for instance, the PC would be updated to the target address given by the branch instruction if the result was 0. If not, the computer would just go on to the following instruction in the sequence. Therefore, the address supplied by the branch instruction that was taken because the condition was true would be the PC target address following a subtraction that results in 0.