Lewis acids among the following area) CCl4 b) SiCl4 c) GeF4

due to lack of empty d-orbitals CCl4 can't acts as lewis acid [Electron pair acceptor]Due to the presence of empty d-orbitals in its valency shell SiCl4 can accepts the electron pair from lewis bases, hence it can acts as lawis acid→ GeF4 also has empty d-orbital in its valency shell hence acts as lewis acid