The following compounds have been arranged in order of their increasing thermal stabilities. Identify the correct order.

K₂CO₃(I), MgCO₃(II), CaCO₃(III), BeCO₃(IV)

(A) I < II< III< IV

(B) IV < II< III< I

(C) IV < II< I< III

(D) II< IV < III< I