Answer:
There is 254 counties in Texas, making it the state with the highest number of counties.
Explanation:
The subject and the verb have to agree when it comes to quantity. They have to be both single or both plural for them to agree.
There are more than one county in Texas. The linking verb "is" needs to be changed to "are".
It should be:
There are 254 counties in Texas, making it the state with the highest number of counties. Georgia has the second highest number with 159 counties.
