In the context of permissible noise level match List-I with List-II anda) (Permissible Noise Level)A.Residential area 1. 50 dbB.Silent zone2.55 dbC.Industrial area3.65 dbD.Commercial area4.70 dbCode: A B C D

1. A

   2 1 3 4

   Option A matches Residential area with 55 dB, Silent zone with 50 dB, Industrial area with 65 dB, and Commercial area with 70 dB, which yields the sequence 2 1 3 4. However, this sequence incorrectly assigns 65 dB to the industrial zone instead of 70 dB. Therefore, this option is incorrect.

2. B

   3 4 2 1

   Option B presents the sequence 3 4 2 1, starting with 65 dB for the residential area. This level exceeds the prescribed limit for residential zones. Thus, this alternative is rejected.

3. C

   2 1 4 3

   Option C pairs Residential area with 55 dB, Silent zone with 50 dB, Industrial area with 70 dB, and Commercial area with 65 dB, producing the correct sequence 2 1 4 3. These noise standards are laid down under the Noise Pollution (Regulation and Control) Rules framed under the Environment (Protection) Act, 1986. This comprehensive alignment satisfies all statutory norms established for different zones, making it the officially designated correct key.

4. D

   1 2 3 4

   Option D suggests the sequence 1 2 3 4, assigning 50 dB to the residential area, which actually applies to the silent zone. Consequently, this arrangement fails to match the statutory noise limits correctly.

Summary. Official key is (c) because it accurately pairs each designated urban zone with its respective permissible day-time noise level standard as per environmental regulations. Residential areas permit up to 55 dB, while silent zones have a stricter limit of 50 dB. Industrial zones tolerate the highest level at 70 dB, and commercial areas are restricted to 65 dB. This precise matching yields the code sequence 2 1 4 3. Aspirants frequently confuse the commercial and industrial limits, but statutory rules clearly place industry at the highest decibel threshold.