Answer:
straight angle
Step-by-step explanation:
A straight line is 180 degrees..for example, the one in the picture
a reflex angle is more than 180 degrees (half a cirlce) but less than 360 degrees (a full circle), therefore it cannot be a straight line unlike the one in the picture
an acute angle is an angle less than 90 degrees which also means it can't be straight
A right angle is 90 degrees, ( like this L) and just like the previous ones, it's not a straight line.
That leaves us with straight line..which is the right answer
