Which of the following sentences is punctuated correctly?

a

The Little League baseball fields near San Diego California are clean and well-lit.
b

The Little League baseball fields near San Diego, California, are clean and well-lit.
c

The Little League baseball fields near San Diego, California are clean and well-lit.
d

The Little League baseball fields near San Diego, California are clean, and well-lit.

The correct sentence is:

b

The Little League baseball fields near San Diego, California, are clean and well-lit.

The correct sentence is (b) "The Little League baseball fields near San Diego, California, are clean and well-lit." This sentence uses commas to set off the state name ("California") as well as to separate the location ("San Diego") and the state name. Additionally, it does not use a comma before the coordinating conjunction "and."