Answer : Option C

Explanation :

The value of actual expression [24.23 * 1.423 * 34.21]/ [521.3 * 413.32 * 2.53] = 0.002163
Now, According to option a [2423*1423*3421]/ [5213*41332*253] = 0.2163
Now, According to option b [242.3*142.3*3421]/ [5213*4133.2*2.53] = 2.1637
Now, according to option c [2.423*14.23*342.1]/ [521.3*4133.2*2.53] = 0.002163
The option C gives the same value as the actual expression, so it is the correct answer.

Solution 2:

The original expression [24.23 * 1.423 * 34.21]/ [521.3 * 413.32 * 2.53] can be written as
[2423*1423*3421*10*100*100]/ [5213*41332*253*100*1000*100]
Or, [2423*1423*3421*10⁵]/ [5213*41332*253*10⁷]
Or, [2423*1423*3421]/[5213*41332*253*10²].......... (i)
Now, according to option a [2423*1423*3421]/ [5213*41332*253]......... (ii)
Now, according to option b [2423*1423*3421*10³]/ [5213*41332*253*10²]
Or, [2423*1423*3421*10]/ [5213*41332*253]........ (iii)
Now, according to option c [2423*1423*3421*10⁴]/ [5213*41332*253*10⁶]
Or, [2423*1423*3421]/ [5213*41332*253*102].......... (iv)

Since, equation i and iv have the same power of 10 in the denominator.

Hence, we can say option C is the same as the actual expression.