Select the correctly punctuated sentence.

A. Fayyaz’s neighbours were terrible, so his brother’s friends went round to have a word.
B. Fayyaz’s neighbours were terrible; so his brother’s friends went round to have a word.
C. Fayyaz’s neighbours were terrible so his brother’s friends went round to have a word.
D. Fayyaz’s neighbours were terrible: so his brother’s friends went round to have a word.