Respuesta :
The library opens at 10:00 a.m. Saturday. - if a time is involved it's safe to assume that it belongs in the time frame.
Answer: the correct answer is the library opens at 10:00 a. m. Saturday
Explanation: it is correct to use colons to separate hours and minutes when we write the time. In the other options colons are not necessary and a semi colon is not appropiate.