An integer is one that isn't a fraction or a decimal.
-3/4 is a fraction, which converts to -0.75
1/5 is also a fraction and it is equal to 0.2
This is why we can rule out choices A and B. Choice D is a similar story.
Put another way, an integer is a whole number that is used to count people, places, things, etc.
Note: choice D is a mixed number consisting of a whole part (4) and a fractional part (2/3). This converts to the improper fraction 14/3, and that converts to the approximate decimal form of 4.67
