Block Difficulty:
A) is determined by the Ethereum Committee every fortnight to reflect the average amount of transaction and it cannot be influenced by the network itself.
B) increases when the time between mined blocks is below 10 seconds, while it decreases when the time is above 20 seconds.
C) increases when the time between mined blocks is below 20 seconds, while it decreases when the time is above 60 seconds.

Question

Quizplus · Accepted Answer

Block difficulty is adjusted automatically by the network to maintain an average block time of 13 seconds. When the time between mined blocks is below 10 seconds, the difficulty increases to slow down block production. When the time is above 20 seconds, the difficulty decreases to speed up block production.