One of the statements below contains a word used incorrectly. Choose the option which has the incorrect or inappropriate usage of the word.

The contrast that is to be captured here is the set of two words 'all together', which simply means all together, and the word 'altogether', which means 'as a whole' or 'totally'. All of options A, C, and D have the correct usage of the phrase 'all together'. While option A refers to 'we' as all together, option C and D respectively refer to the three hundred guests and the participants.

Option B has the incorrect usage of the phrase 'all together', as it should instead be 'altogether'. The sentence is trying to say that although the son is not interested in watching movies, it is not 'entirely' a bad thing. 'all together' is an incorrect usage in B, and it is therefore the correct answer.