Dinosaurs, birds, early mammals and plants were major life-forms that existed in a. mesozoic era c. cenozoic era b. paleozoic era d. devonian era select the best answer from the choices provided a b c d

Option A, Mesozoic Era, is the right answer.

The Mesozoic era is one of the three geologic eras. The Triassic, Jurassic, and Cretaceous are the three subdivided periods of this era. The era observed the progressive rifting of Pangaea (the super-continent) into various landmasses. The climatic conditions during this time varied from warming to cooling. Dinosaurs in the Mid-Triassic period appeared on the earth for the first time. The appearance of birds can be seen in the Jurassic period (though, actual toothless birds emerged initially in the Cretaceous). The early mammals also emerged throughout the Mesozoic era but would endure small.

the electromagnetic spectrum includes, from longest wavelength to shortest: radio waves, microwaves, infrared, optical, ultraviolet, x-rays, and gamma-rays.

c is the answer : )               your welcome