H1B, H4 Visa

Hi Guys,

Its really great to know all the possible questions/answers for H-1B / H4 but I have few specific doubts:

1) I am working in company A in India.
2) Petitioner is company B in USA who is fully own subsidiary of Company A

- If VO asks "Briefly describe your duties" - do I describe my current duties in current company A or I need to explain the duties that I will be performing at company B? OR VO will be specific in mentioning "on-site" etc?

- What should be my reference point DS-160? or I-129 for "Job responsibilities"?

- Note that there is bit of a difference in job duties mentioned in DS-160 & I-129 - & so the doubt. In DS-160 I have mentioned "Design & Development of customized SW applications..." whereas in I-129 is on lines of "Design of Test Plans, test cases, test case execution, result & bug reporting... etc etc". (I actually perform both kind of duties - but its about what to answer - as per DS-160 or I-129?)

- So what's my best answer here ? I can think of two short & precise sentences including both answers:
           - As a xxxx I shall be responsible for,
             Design of Test Plans, Test case execution & bug reporting And,
             Design & development of customized SW applications tools.

- Million dollar question :) - What does VO refer to - to cross verify our answers? DS-160, I-129 or Both?

Answers to my queries will be highly appreciated. Kindly help!!!