challenge: Which venture capital firms invested $21 million in Vector Launch, Inc. in June 2017?
  
  A. Khosla Ventures, Founders Fund, and Lightspeed Venture Partners
  B. Sequoia Capital, Shasta Ventures, and Lightspeed Venture Partners
  C. Sequoia Capital, Shasta Ventures, and Andreessen Horowitz
  D. Benchmark, Greylock Partners, and Sequoia Capital
  Answer: 