Holding company

As per Sub-section (2) of Section 129,Where a company has one or more subsidiaries or associate companies, it shall, in addition to financial statements provided under sub-section [2], prepare a consolidated financial statement of the company and of all the subsidiaries and associate companies in the same form and manner as that of its own and in accordance with applicable accounting standards, which shall also be laid before the annual general meeting of the company along with the laying of its financial statement under sub-section [2]:

So A Ltd. will have to prepare its Standalone Financial Statement and Consolidated Financial Statement of A Ltd.,B Ltd. and C Ltd.

For B Ltd. is required to prepare its Standalone Financial Statement and Consolidated Financial Statement of B Ltd. and C Ltd.