Which of the following is part of the theory about the Earth's magnetic field?

A. It has to do with the rocks on the surface on the Earth
B. The theory states that the north and south poles have more iron and nickel than other places on Earth
C. The theory states that the magnetic field is created by molten iron and nickel circulating in the Earth's core
D. The theory states that the magnetic field is created by man

Hydrilla (hydrilla verticillata) is an invasive aquatic plant and one of the most serious aquatic pests in florida. hydrilla has already been introduced to hundreds of bodies of water throughout florida, hydrilla is difficult to control because it grows rapidly and survives in many different water depths and conditions. hydrilla • describe how hydrilla affects native plant and animal species. include both a biotic and an abiotic limiting factor. • suggest one biotic and one abiotic recommendation that could slow the spread of hydrilla