Problem: How does the sentence end?

Laura bumped their head in the accident but Elena was uninjured. 
OPTIONS:
- Laura didn't have a case of amnesia.
- Elena didn't have a case of amnesia.
Answer: Elena didn't have a case of amnesia.

Problem: How does the sentence end?

The stains could not be removed with detergent, but the soap did the job.  The 
OPTIONS:
- detergent was weak in cleaning power.
- soap was weak in cleaning power.
Answer: detergent was weak in cleaning power.

Problem: How does the sentence end?

He wanted to preserve the tomatoes and the onions, but the 
OPTIONS:
- tomatoes gave him difficulty because of the fumes.
- onions gave him difficulty because of the fumes.
Answer: onions gave him difficulty because of the fumes.

Problem: How does the sentence end?

The TV won't fit into the existing cabinet because the 
OPTIONS:
- TV is a bit too little.
- cabinet is a bit too little.
Answer:
cabinet is a bit too little.