Correct option is D
The segment
"they has written" contains the grammatical error.
· The correct form should be "they have written" to agree with the plural subject "they."
·
Grammatical rule: The verb must agree in number and person with its subject. Here, "have" is the correct plural form of the auxiliary verb to use with "they."
·
Example: They have completed their tasks efficiently, using the correct verb form for a plural subject.