Final answer:
The phrase 'without doubt' in the given sentence is an adverbial phrase that modifies the adjective 'caring'.
Step-by-step explanation:
In the given sentence, the phrase 'without doubt' is functioning as an adverbial phrase. This phrase modifies the adjective 'caring' by adding emphasis and certainty to it.
Adverbial phrases typically modify verbs, adjectives, or other adverbs, providing additional information such as time, manner, place, or degree.
Learn more about Adverbial phrases