You are a semiconductor device modeling consultant and you are asked to recommend strategies to increase the current IDS of a new MOSFET for a given VGS and VDS without increasing the width of the device. Which of the following statements are correct recommendations?

a. Select a material for the oxide with lower permitivity, decrease the thickness of the oxide layer, decrease the channel length, increase the mobility of the carriers by using a n-channel instead of p-channel device, and attempt to decrease the threshold voltage.
b. Select a material for the oxide with higher permitivity, decrease the thickness of the oxide layer, decrease the channel length, increase the mobility of the carriers by using a n-channel instead of p-channel device, and attempt to decrease the threshold voltage.
c. Select a material for the oxide with higher permitivity, decrease the thickness of the oxide layer, decrease the channel length, decrease the mobility of the carriers by using a p-channel instead of n-channel device, and attempt to decrease the threshold voltage.
d. Select a material for the oxide with higher permitivity, decrease the thickness of the oxide layer, decrease the channel length, increase the mobility of the carriers by using a n-channel instead of p-channel device, and attempt to increase the threshold voltage.