a double variable stores a value in 64 bits, using some bits for mantissa, some for exponent, and one for sign. which is true about a double variable? a. limited bits may cause some rounding of the mantissa. b. if a value is too large for a double, a float should be used instead. c. if a value is too large for a double, a long should be used instead. d. the compiler may sometimes use 63 bits for the mantissa. 1 points