Option A) False. It is possible that 2 different devices have same Physical addresses (MAC addresses) on a global level. This happens because MAC addresses are given by manufacturers and they do reuse the addresses. Also, had the physical addresses been globally unique (and hierarchical) we could have just used those instead of IP addresses for global communication.
Option B) False. The entire parity check scheme can detect only odd bit errors. But here they’ve given SINGLE PARITY CHECK which can detect only 1 bit error.
Option C) False. There is no reason for a station to not get the channel access. All stations continuously sense the channel. Ethernet uses 1 -persistent method with CSMA/CD. Whenever channel is sensed idle, station transmits with 100% probability. While transmitting as well, it keeps on sensing, so even if if there is a collision, the station will go into back-off and try again later.