ATmega328P 16MHz or higher clock output on CLKO pin
Verify your fuse bits settings:


You should choose full swing crystal oscillator, that is CKSEL3...1 should be 011.
Then you can choose "Crystal Oscillator, slowly rising power", that is CKSEL0 is 1 and SUT1..0 is 11.
You selected 8MHz - why? If you use 16 MHz thats not the right setting.
CLKO pin will output system clock - that can be divided by the prescaler.
See chapter 9.12.2 in the datasheet. Register CLKPR should have bits CLKPS3...0 set to 0, so it gives prescaler value of 1.
That is make sure the fuse bit CKDIV8 is not enabled, as this will divide the clock by 8.


So it is more probably that 0xB7 is the correct settings, not the 0xBF. See this calculator