What is the penalty for not getting the accounts audited as required by section 44AB?

According to section 271B, if any person who is required to comply with section 44AB fails to get his accounts audited in respect of any year or years as required under section 44AB, the Assessing Officer may impose a penalty. The penalty shall be lower of the following amounts:

(a) 0.5% of the total sales, turnover or gross receipts, as the case may be, in business, or of the gross receipts in profession, in such year or years.

(b) Rs. 1,50,000.

However, according to section 273B​, no penalty shall be imposed if reasonable cause for such failure is proved.