Mustafizur Rahman beautifully delivered the ball. Here 'beautifully' is -

• 'Adverb of manner' tells us how something happens.
They are usually placed either after the main verb or after the object.
For example- beautifully, quickly, softly, loudly etc.

• Adverb of degree tells us about the intensity of something.
They are usually placed before the adjective, adverb, or verb that they modify, although there are some exceptions.
The words "too", "enough", "very", and "extremely" are examples of adverbs of degree.

• Adverb of Affirmation is a word that declares that something is true or some equivalent expression or negative statement, judgment, or a logical proposition.
For example- certainly, definitely, obviously, surely.

• Adverb of frequency describes how often an action happens.
There are six main adverbs of frequency: Always, usually (or normally), often, sometimes, rarely, and never.

Hence, the correct answer is 'Adverb of manner'.