Adaface Sample Solidity Questions

Review the following Solidity code:

We want to add a fallback function to the contract. Pick the correct fallback function and correct statements:

E: Fallback function is executed if contract receives plain Ether without any data
            F: Fallback function is executed if caller calls a function that is not available
            G: If multiple unnamed functions are defined for a contract, the cheapest function is used as fallback function

Review the following Solidity code:

Pick the correct statements:
            
            A: private increment function defined in contract_e is accessible in derived contract d_c but not accessible outside the derived contracts.
            B: private increment function defined in contract_e is accessible only inside contract_e and not accessible to derived contracts as well.
            C: internal variable str defined in contract_e is accessible in derived contract d_b but not outside the derived contracts.
            D: internal variable str defined in contract_e is accessible only inside contract_e and not accessible to derived contracts as well.