Responsibility for completing the task/ to complete the task

#1 sounds better to me.

Thank you, Mister Micawber.

Let me make sure of one thing.

In the following context, which of them is idomatic? If none, could you tell me an idomatic expression?

A: You are the leader of the group. I think you have the responsibility.

B: I'm afraid I was the leader of the group last week, not this week. I had the responsibity (to complete/for complet

'For completing' still seems the natural alternative.

Thank you, Mister Micawber.

Let me ask once again.

In the following context, is it idiomatic to use "the responsibility to complete"?

A; I got the commandment from the authorities. It imposes the responsibility on you.

B; I don't think I have the responsibility to complete the task even if the commandment says I should take it.

Thanks i

Yes, that sounds fine.