Gas costs of calling a function within the same contract

Smart Contracts
1

What is the reason for the ~1300 extra gas on by calling B & E compared to D?

Above each method is the gas cost when called directly.

pragma solidity ^0.8.0;
contract A{
    // 23620 gas
    function B () public returns (bytes memory) {
       (bool success, bytes memory data) =             
    address(this).call(abi.encodeWithSignature("C(uint256)",92) );
        return data;
    }

    // 22000 gas
    function C (uint256 c) public returns (uint256){
        return 5 + c;
    }

    // 22070 gas
    function D (uint256 d) public returns (uint256){     
        C(d);
        return d;
    }
    //23277 gas
    function E (uint256 d) public returns (uint256){
    this.C(d);
    return d;
    }
}

Is there any way to variably call a function within a given contract variably with similar gas costs to function D?