Answer:
To store decimal values
Explanation:
Analyzing the given options.
(a)
Decimal values are digits and are to be treated as such. So, storing them as strings mean that they are no longer decimal values.
(b), (c) & (d)
List of colors, words and values that can't be used for calculations are all string values.
Take a for instance.
List of colors: "Red", "Yellow", "Blue",...
Words, "I", "am", "a", "boy"
Values that can't be used for calculations are non numerical data and as such, some of them could be strings.
Hence:
Option (a) answers the question
