The numeral in the working days for the HO to take up a representation is:

This question concerns the initial internal processing time for a Head Office (HO) to commence action on a received representation. 3 working days is the correct answer, reflecting an efficient yet practical timeframe for administrative intake.

• Option A (1 working day) might be overly ambitious for all cases, especially considering potential internal routing and initial checks.
• Option C (5 working days) and Option D (7 working days) could be perceived as slightly slow for the initial step of 'taking up' a representation, which implies acknowledging receipt and beginning the formal process.

Three working days ensures prompt attention to representations while allowing for necessary internal administrative procedures.