1-Name the first president to die in the office (while president)

my answer is William Henry Harrison
do you agree ?

Yes.

Yes, I agree with your answer. William Henry Harrison is indeed the first president to die while in office. He served as the ninth president of the United States and died on April 4, 1841, just one month after his inauguration. To verify this information, you can refer to historical records, encyclopedias, or official government websites that provide details about the presidency of William Henry Harrison and his untimely death.