Question

The round cake was cut using a rectangular grid, the outer pieces were different shapes and sizes.

What is the best way to rewrite this sentence?
a. The round cake was cut using a rectangular grid: the outer pieces were different shapes and sizes.
b. The round cake was cut using a rectangular grid, but the outer pieces were different shapes and sizes.
c.The round cake was cut using a rectangular grid, so the outer pieces were different shapes and sizes.
d. The round cake was cut using a rectangular grid, because the outer pieces were different shapes and sizes.

Answer 1

The best way to rewrite the sentence above is:

b. The round cake was cut using a rectangular grid, but the outer pieces were different shapes and sizes.

Comma is used to separate two independent clauses. The ideas conveyed are contrasts therefore the use of the conjunction "but" is inserted.