Young people need to do the following in order to get a nine hour sleep:

(A) switch off electronics before bedtime

(B) switch off all electronics for the night

(C) find quiet time before bedtime

(D) find a quiet time & place to sleep

Choose the correct answer from the options given below:

The correct answer is (B) and (C) only.

To understand why this is the correct choice, let us analyze the conditions required for young people to achieve a healthy nine-hour sleep:
1. Switching off all electronics for the night (B): Keeping electronic devices on during the night, even on silent or vibrate mode, can cause disruptions due to notifications, blue light emissions, or the temptation to check messages. Turning them off completely ensures an uninterrupted sleep environment.
2. Finding quiet time before bedtime (C): Engaging in relaxing, low-stimulation activities (quiet time) right before going to bed helps transition the brain and body into sleep mode, making it easier to fall asleep and stay asleep for the recommended duration.

Let us look at why the other statements do not fully address the requirements:
- Statement (A) suggests switching off electronics only before bedtime, which is helpful but does not prevent middle-of-the-night disturbances if they are left on during the night (making B a more comprehensive and necessary condition).
- Statement (D) mentions finding a quiet time & place to sleep, but finding a "quiet time to sleep" is redundant and less precise compared to establishing a calming transition routine (quiet time before bedtime) and securing an electronics-free night environment.

Therefore, the combination of switching off all electronics for the night and finding quiet time before bedtime represents the most effective set of habits to secure a nine-hour sleep. This corresponds to the option (B) and (C) only.