There are 50 sections.
Step-by-step explanation:
Given,
Length of section = 10 meters
Total length of guardrail = 0.5 km
We will convert this length in meters.
1 km = 1000 meters
0.5 km = 0.5*1000 = 500 meters
Now,
No. of sections = 
No. of sections = 
No. of sections = 50
There are 50 sections.
The correct way is > that symbol
The answer is D positive 1/2
The answer would be c: Regulatory proteins blind to repressor.