Under similar warm, moist climatic conditions, why would basalt and gabbro generally have higher ...

Under similar warm, moist climatic conditions, why would basalt and gabbro generally have higher chemical weathering rates than rhyolite and granite?
 
  A) The quartz in the gabbro and basalt decomposes very quickly.
  B) The potassium feldspars and quartz in the rhyolite and granite are more susceptible to cracking by frost wedging.
  C) The plagioclase feldspars in the granite and rhyolite decompose readily to clay minerals and iron oxides.
  D) The ferromagnesian minerals in the gabbro and basalt are subject to oxidation and chemical breakdown.