It won't move. Is it the drive belt?

hello sir, loss of power or transmission will not operate in either direction.a, broken or slopping drive belt.b. broken speed control linkage.c, low transmission oil level.d, wrong transmission oil or contaminated oil. e, transmission oil too hot. f, transmission roll release valve in wrong position.g, plugged oil filter.h, faulty charge pump or charge pressure relief valve. i, worn or damaged transmission pump and/or motor. j, drive pulley slipping on the transmission input shsft. k, internal damage to the reduction gear assembly. this is for a hydrostatic transaxle transmission, though i would give you something to do and check,hope this helps,MrFixIt,oh could you please rate this solution,thank you.