1. (b) You are right, but read on to check your reasoning.

You should have chosen to apply 'expressio unius' to the phrase 'chickens and ducks'.

The result of applying this principle is that 'chickens and ducks' is interpreted narrowly, not to include any other domestic poultry.

You should have decided that the phrase 'chickens and ducks' on its own does not provide any basis for the application of 'ex abundanti cautela'.