Identifying the major drawback of a basic S-R latch: Among the listed characteristics, which one is the well-known limitation that makes the raw S-R latch less convenient than more advanced primitives such as J-K or D devices?

Introduction / Context: The S-R latch is widely taught because it illustrates fundamental bistable feedback. However, one of its input combinations leads to an undefined or forbidden state, and this drawback motivates the use of J-K and D-type primitives in many designs.

Given Data / Assumptions:

• We consider the classic S-R latch using NOR (active-HIGH) or NAND (active-LOW) gating.
• Outputs are Q and Q’ with complementary feedback.
• We assess which listed characteristic is the key limitation in practical use.

Concept / Approach: For a NOR-based S-R latch, S=1 and R=1 is invalid since both outputs are forced LOW before returning to indeterminate complements. For a NAND-based latch, S̅=0 and R̅=0 is the forbidden case. This invalid/undefined condition complicates input conditioning and can cause racing or metastability if not carefully avoided.

Step-by-Step Solution:

Verification / Alternative check:

Why Other Options Are Wrong:

Common Pitfalls:

Final Answer: