A Offers £300 in Return for Information About His Missing

A offers £300 in return for information about his missing dog. B, A's neighbour, witnessed the dog being abducted and duly informs A. In which scenario would B be entitled to the reward? Please select all that apply.

A) Whilst on the way to A's house, B sees a poster advertising the reward, but is uninterested.
B) B heard about a reward offered for a lost pet on the radio but did not realise the pet in question was A's dog.
C) B heard about the reward after informing A.
D) B learns about the reward during his conversation with A.