What format of certificate encoding is incompatible with ChromeOS devices?

What format of certificate encoding is incompatible with ChromeOS devices?
A . PEM
B . CER
C . DER
D . CRT

Answer: C

Explanation:

ChromeOS primarily uses the PEM format for certificate encoding. While it can handle other formats like CER and CRT, it does not support the DER format. DER is a binary format, while ChromeOS requires certificates in a text-based format.