Which is a run-on sentence?

A.
Apples are generally red, but there are some golden varieties.

B.
Keys are made for each lock, yet many keys look the same.

C.
Flamingos are usually pink one variety is bright red.

D.
Sailboats use wind power, but many sailboats also have a motor.

Question

Which is a run-on sentence?	
 
 A.
Apples are generally red, but there are some golden varieties.
 
 B.
Keys are made for each lock, yet many keys look the same.
 
 C.
Flamingos are usually pink one variety is bright red.
 
 D.
Sailboats use wind power, but many sailboats also have a motor.

anonymous · Answer

any ideas?

anonymous · Answer

Which do you think it is?

anonymous · Answer

C. Because it should be Flamingo are usually pink. But, one variety is bright red.

anonymous · Answer

We aren't supposed to give direct answers, lol..

@Smileyside | @ItsRhiBish

anonymous · Answer

she gave a reason why and i didnt say it was just c, i said its obvious

anonymous · Answer

I explained why. So maybe next time he/she could know what to look for.

anonymous · Answer

C because there should be a comma there, and it shouldn't run on. Simple as that. It should be "Flamingos are usually pink, one variety is bright red." Or "Flamingos are usually pink. But, one variety is bright red."