For predicting the straight-line trend in the sales of washing machines (in thousands) on the basis of 8 consecutive years data, the company calculates 4 year moving averages. If the sales of washing machines for respective years are a, b, c, d, e, f, g and h, then which of the following averages will be computed?

(A) $\frac{a+b+c+d}{4}$
(B) $\frac{a+c+d+e}{4}$
(C) $\frac{c+d+f+h}{4}$
(D) $\frac{b+c+d+e}{4}$

Choose the correct answer from the options given below:

(A) and (D) only

The correct answer is Option (2) → (A) and (D) only

$\text{4-year moving averages from } a,b,c,d,e,f,g,h \text{ are:}$

$\frac{a+b+c+d}{4},\;\frac{b+c+d+e}{4},\;\frac{c+d+e+f}{4},\;\frac{d+e+f+g}{4},\;\frac{e+f+g+h}{4}.$

$\text{Hence } \frac{a+b+c+d}{4} \text{ and } \frac{b+c+d+e}{4} \text{ are both computed.}$

$\text{Correct options: (A) and (D).}$