In the context of Panchayati Raj, which of the following are recommendations of Balwant Rai Mehta Committee (1957)?
A. Establishment of a three-tier Panchayati Raj system gram panchayat at village level (direct election), panchayat Samiti at the block level and Zila Parishad at the district level (indirect election)
B. District Collector to be the chairman of Zila Parishad
C. Constitutional recognition to be given to Panchayati Raj institutions
D. Transfer of resources and power to these bodies to be ensured