In this task, you need to count the number of words in a sentence that start with the given letter. Answer with numbers and not words.

Sentence: 'a baseball player prepares to swing at a pitch'. How many words start with the letter 'a' in the sentence.
3

Sentence: 'a vine of bananas sit on a tree'. How many words start with the letter 'b' in the sentence.
1

Sentence: 'a woman is holding an open red umbrella over her head'. How many words start with the letter 'o' in the sentence.

2