Concept:Word formation is the process of creating new words from existing ones. Two main methods are compounding and affixation.Explanation:Compounding joins two separate words to form a new word, like "earthquake" (earth + quake). The new word has a meaning different from the original two words.Affixation adds a prefix or suffix to a root word to change its meaning or grammatical role, e.g., "happy" to "unhappy" (prefix) or "happiness" (suffix).Both compounding and affixes are systematic rules that expand vocabulary in a language.Answer:Option A: compounding and affixes