A. Holding her note cards, the woman stepped up to the microphone ready to give her speech. This is correct-o!
B. This is wrong. "The woman stepped up to the microphone ready to give her speech holding her note cards." The sentence is too long and very complicated.
C. This is also complicated and doesnt really make sense. "The woman stepped up to the microphone holding her note cards ready to give her speech."
D. This one makes sense, but there can be any woman holding note cards. "Ready to give her speech, the woman holding her note cards stepped up to the microphone."