QUES: Serve with option of lettuce tomato sour cream or guacamole and extra salsa as desired

correct the punctuation.

CORRECTED: Serve with option of lettuce, tomato, sour cream or guacamole and extra salsa as desired.

QUES: dynamic working environment and professional in a multinational company

correct the punctuation.

CORRECTED: -dynamic working environment and professional in a multinational company.

QUES: SERO Solutions is a wireless systems integrator based in the UK with a focus on Mobile technologies

correct the punctuation.

CORRECTED:
SERO Solutions is a wireless systems integrator based in the UK with a focus on Mobile technologies.