Exam 300-425 topic 1 question 12 discussion

B is correct answer, since the cinder block made with ash or cinder and they have less attenuation compare to concrete block.

metal door

Metal has most attenuation

Study guide Table 2-2 Common Obstacles and Their Estimated Attenuation Values Object in Signal Path Signal Attenuation Through the Object Plasterboard wall 3 dB Glass wall with metal frame 6 dB Cinderblock wall 4 dB Office window 1–3 dB Metal door 6 dB Brick wall 8 dB Concrete wall 12 dB Phone and body position 3–6 dB Phone near field absorption Up to 15 dB