In this task, you need to count the number of times the given letter appears in the given sentence.

[Q]: Sentence: 'a man with headphones on is hunched over a sink while being recorded'. Find frequency of the letter 'd'
[A]: 4

[Q]: Sentence: 'a bunch of cows that are in the field'. Find frequency of the letter 'a'
[A]: 3

[Q]: Sentence: 'two giraffes standing in a dirt lot next to a building'. Find frequency of the letter 'n'
[A]:
5