When we're reporting a speech, we're narrating things that happened
or were said in the past. So, the speech will go one tense back.
In
reported speech, we add a reporting verb (usually 'said'), the subject
changes in narration ('he', 'she' or 'they') and the related words also
change.
Option B: For reporting the speech of the Sales Girl, 'we'
changes to 'they', as the point of view has changed. 'Do not' is in the
simple present, it changes to 'did not', the simple past verb.
So, the corrected reported speech for the sentence "Sorry sir, we don't stock 'wonder drugs'." is:
'The sales girl remarked apologetically that they did not store 'wonder drugs'.'
Hence option B is correct.
Since, 'sorry' does not have a suitable form in the indirect speech, we use the word 'apologetically' that explains the manner in which the sales girl spoke.
Option A: The word 'excitedly' does not describe the manner in which the sales girl spoke. It does not mean the same as 'sorry'.
Option C: The point of view 'we' hasn't been changed here.
Option D: 'We' has not been changed to third person 'they', and 'excitedly' does not refer to the word 'sorry'.
Hence these options A, C and D are incorrect.