Why do cordless devices, such as cordless telephones, sometimes interfere with wireless access points?

Why do cordless devices, such as cordless telephones, sometimes interfere with wireless access points?

• These devices operate at similar frequencies.
• These devices operate at the same frequencies and have higher RF power settings.
• These devices flood the entire frequency spectrum with low power noise, which may cause loss of signal for wireless devices trying to connect with an access point.
• The signal from the cordless device is non-polarized and combines with the access point polarized signal, thus reducing overall signal strength.

Exam with this question: CCNA 3 Exploration v4.0 Chapter 7 Quiz