Concept:Define variables for number of tables (x) and chairs (y) and translate cost and space limits into inequalities.Explanation:Let x be the number of tables and y be the number of chairs.Cost constraint: 400x+100y≤10000. Divide by 100: 4x+y≤100.Space constraint: x+y≤100.Non‑negativity: x≥0, y≥0.Answer:x+y≤100, 4x+y≤100, x≥0, y≥0 which matches option A.