Select the correct statements$)$ regarding baud rate and bit rate.O a$.$ baud rate always equals bit rate, and the terms can be used interchangeably O b$.$ by increasing a symbol's $"$M$"$ value, bit rate is increasedO c$.$ by decreasing a symbol's $"$M$"$ value, we increase the number of bits that a symbol can representO d$.$ all of the above are correct