The correct method of stating 4,500 feet MSL to ATC is
A.	“FOUR POINT FIVE.”
B.	“FOUR THOUSAND FIVE HUNDRED.”
C.	“FORTY-FIVE HUNDRED FEET MSL.”

Answer (A) is incorrect.
Four point five is slang (not correct) phraseology.

When calling out altitudes up to, but not including, 18,000 ft., state the separate digits of the thousands, plus the hundreds, if appropriate (e.g., 4,500 ft. = four thousand five hundred).
Unless otherwise noted, the altitudes are MSL.

Answer (B) is correct. (AIM Para 4-2-9) ( ? )
The proper phraseology for altitudes up to but not including 18,000 feet MSL is to state the separate digits of the thousands, plus the hundreds, if appropriate. It would be “four thousand, five hundred.”