Draw the bondline structure for the amine: dipropylamine

Bondline structure of dipropylamine with two propyl groups attached to a nitrogen atom.

Bondline structure of dipropylamine with two propyl groups on either side of a nitrogen atom.

Bondline structure of dipropylamine showing a nitrogen atom between two propyl groups.

Bondline structure of dipropylamine with a nitrogen atom connected to two propyl groups.