Step 1: Provision under Section 4(5).
If the name of a company is identical or too similar to an existing company or trademark, the Registrar has the power to direct the company to change its name.
Step 2: Clarification.
The Registrar does not have the power to strike off the name or wind up a company on his own under this section. His authority is limited to directing a name change.
Step 3: Conclusion.
Thus, option (a) is correct.