Correct option is C
· The phrase "between...to" is incorrect. The correct preposition to use with "between" is "and" instead of "to."
· The correct phrase should be: "between 10th May and 10th June."
· Correct sentence: "Our summer vacation is between 10th May and 10th June."
· Rule: "Between" is always followed by "and," not "to."
Example :She was traveling between Delhi and Mumbai.She was traveling between Delhi to Mumbai. (Incorrect)