Explanation:

Option 2nd is correct.

• The scheme introduced as a well-targeted system of service delivery to LPG customers is called "PAHAL (Pratyaksh Hanstantrit Labh)" which stands for "Direct Benefit Transfer for LPG (DBTL)". 

• Explanation: PAHAL aims to deliver LPG subsidies directly to consumers' bank accounts, ensuring transparency and reducing leakages in the subsidy system. 

Option 1: SAHAJ

• SAHAJ refers to the online process of registering and joining the LPG network but doesn’t specifically relate to a targeted service delivery system.

Option 3: UDAY

• UDAY (Ujwal DISCOM Assurance Yojana) aims to improve the financial health and operational efficiency of power distribution companies in India.

Option 4: UDAN

• UDAN (Ude Desh ka Aam Naagrik) is a regional airport development and connectivity scheme.