GRE Text Completion: Fundamental 24 Sets-GRE填空基础24套 - E1CXJGE1DPFIJ16Y!

Madame C.J. Walker introduced her first hair-care product just as demand was reaching its peak; this ____________ marketing made her a millionaire. A. opportune B. instantaneous C. timely D. dubious E. extravagant F. ephemeral