Which of the following statements is NOT true about solar inverters?

Question

A stand-alone inverter is supposed to work as an AC voltage source for a specified range of AC loads.
An ideal grid-tied inverter has its operational voltage and frequency synchronized with those of the grid.
A bimodal inverter can power backup loads even if the grid-connection is disrupted.
An ideal grid-tied inverter works as a perfect voltage source, and changes the grid voltage and frequency to match its own.