In this task, you need to answer 'Yes' if the given word is the longest word (in terms of number of letters) in the given sentence, else answer 'No'. Note that there could be multiple longest words in a sentence as they can have the same length that is the largest across all words in that sentence.

Example Input: Sentence: 'a hot dog with ketchup and mustard is on a styrofoam plate'. Is 'plate' the longest word in the sentence?
Example Output: No

Example Input: Sentence: 'a toddler looks at a fire hydrant while his mother watches him'. Is 'his' the longest word in the sentence?
Example Output: No

Example Input: Sentence: 'a couple elephants that are walking across a grassy field'. Is 'across' the longest word in the sentence?
Example Output:
No