Explanation:

- Option 1: convencing

- Incorrect spelling. The correct word is "convincing," which means persuading someone with evidence or argument.

- Option 2: conveyence

- Incorrect spelling. The correct word is "conveyance," referring to the action of conveying or transporting something.

- Option 3: commemorate

- Correct spelling. To commemorate means to honor the memory of someone or something, often with a ceremony.

- Option 4: concushion

- Incorrect spelling. The correct word is "concussion," which is a type of brain injury caused by a blow to the head.