The wrong answers for sure are B and D, I assume the answer is C
Ummmm this one is hard but i guess it would be t?????
Answer: The de broglie wavelength is
.
Explanation:
Calculate
as follows.

where,
h = plank's constant = 
p = momentum = 
Putting the values in the formula as follows.

=
= 
Thus, the de broglie wavelength is
.
Formula unit mass is defined as the sum of the mass of all the atoms each multiplied its atomic masses that are present in the empirical formula of a compound. It is expressed in amu.
Atomic mass of calcium = 40 amu
Atomic mass of chlorine = 35.5 amu
Formula mass of CaCl2 = (1 x 40) + (2 x 35.5) = 111amu.