Given body wieght of seven students= 54 kg, 78 kg, 43 kg, 82 kg, 67 kg, 42 kg, 75 kg

We know the formula,

 $\mathrm{Average} \left(\mathrm{A}\right)=\frac{\mathrm{Sum} \mathrm{of} \mathrm{given} \mathrm{values} \left(\mathrm{S}\right)}{\mathrm{Total} \mathrm{number} \mathrm{of} \mathrm{values} \left(\mathrm{N}\right)}$

 Here,

 Sum of given body wieghts (S)

= 54+78+43+82+67+42+75

= 441

Total number of students (N)= 7

Substituting these values we get (A),

 $= \frac{441}{7}=63$

Hence, Option D is correct.