Explanation:

- The sentence is divided into four parts:

1. "There are ten"

2. "students less"

3. "in the class today"

4. "no error"

- Part (1): "There are ten" is grammatically correct. It begins with a quantifier, setting up the context properly.

- Part (2): "students less" contains an error. When talking about countable nouns like "students," the correct form should be "fewer," not "less."

- Part (3): "in the class today" is correct, as it properly identifies where and when the event is happening.

- Part (4): "no error" would be marked if there were no grammatical issues in the sentence.

The correct answer is Option:2 (2) as the error is in part (2).