challenge: What type of domains does the IQGAP2 protein contain?
  
  A. Two IQ domains, one WW domain, and one phosphatase domain
  B. Three IQ domains, one calponin homology domain, one Ras-GAP domain, and one WW domain
  C. One IQ domain, one Ras-GAP domain, and one kinase domain
  D. One IQ domain, one Ras-GAP domain, and one helicase domain
  Answer: 