Final answer:
The question is asking about the classification of the word 'that' as an adverbial.
Step-by-step explanation:
In this question, the phrase 'what type of adverbial is that?' is asking about the classification of the word 'that' as an adverbial. To determine the type of adverbial, we need to understand the function of 'that' in the sentence. Adverbials can describe time, place, manner, or frequency. Without the full context of the sentence, it's difficult to determine the exact type of adverbial 'that' represents.
For example, if the sentence is 'I go to the park that is nearby', 'that' would be a place adverbial.
Without more information, it's not possible to definitively classify 'that' as a specific type of adverbial.