Which of the following best describes a pair of elements that will form an ionic bond?
A. C and H: Hydrogen easily loses electrons, and carbon gains them.
B. Li and O: Oxygen easily loses electrons, and lithium gains them.
C. P and Cl: Phosphorus easily loses electrons, and chlorine gains them.
D. Ca and Br: Calcium easily loses electrons, and bromine gains them.
(It's either A or D but I'm not sure)