Examine the following constitutional mandates and determine which are explicitly codified as obligations of the individual citizen under Article 51A:
1. The mandate to value and safeguard the rich heritage of the nation's composite culture.
2. The mandate to actively protect the weaker societal sections from economic and social injustice.
3. The mandate to cultivate humanism, a spirit of reform, and a scientific temper.
4. The mandate to continuously strive toward excellence across all spheres of individual and collective endeavor.