The following table presents the number of units of a product produced and sold by a company during six years.

In which year, the production of units of the product is approximately 31.4% less than the sale of units in 2017?

This question can be solved by checking each of the options one by one.

Option (a) 2012

Percentage less = $$\frac{\left(630-320\right)}{630}\times\ 100$$

= $$\frac{310}{630}\times\ 100$$

= 49.2%

Option (b) 2016

Percentage less = $$\frac{\left(630-504\right)}{630}\times\ 100$$

= $$\frac{126}{630}\times\ 100$$

= 20%

Option (c) 2014

Percentage less = $$\frac{\left(630-432\right)}{630}\times\ 100$$

= $$\frac{198}{630}\times\ 100$$

= 31.42%

Option (d) 2013

Percentage less = $$\frac{\left(630-338\right)}{630}\times\ 100$$

= $$\frac{292}{630}\times\ 100$$

= 46.34%

So the required percentage is in the year 2014 which is given in option (c).