B could be rewritten, like so -
From "See if the light is red or not illuminated at all, now check that the ethernet cable connecting the router and computer is securely attached"
To "Check if the light is red, or not illuminated at all. IF so, THEN check the ethernet cable connecting the router to the computer is securely attached"
The Himalayas mountain range
The Umayyads were the first Muslim dynasty to achieve success after caliph rule.