Consider the following statements :

i. The failure of many structures

ii. Accidents on major highways

iii. Discharge of effluents which pollute rivers

iv. Dangerous gas emissions

These are attributable to :

1. Improper design

2. Not adhering to proper maintenance practices

3. Lack of proper inspection and quality control during construction

4. Corruption amongst several con-caned individuals

5. Lack of public concern

Select the most appropriate answer using the codes given below :