In the short run, a firm's total costs are the sum of Average costs and marginal costs. Input costs and output costs. Total fixed costs and total variable costs. Fixed costs and average costs. Marginal costs and variable costs. Average variable cost equals Total cost divided by output Total variable cost divided by output. Total cost minus total variable cost. Average total cost pluses average variable cost. Total fixed cost minus total variable cost. In addition to preferences, a consumer's choice is further constrained by a Income and commodity prices. Nothing. A rising marginal utility curve. An equilibrium market where utility is minimized. The fact the optimal market basket is rarely in the equilibrium market basket