The rising portion of the long-run average cost curve of a firm is an indication that it is experiencing

The rising portion of the long-run average cost curve of a firm is an indication that it is experiencing diseconomies of scale. This means that as the firm expands its production in the long run, its average costs increase. This could be due to various factors such as a lack of coordination among workers, increased managerial complexity, or increased transportation costs. In other words, the firm is no longer benefiting from economies of scale and is experiencing diminishing returns to scale. This is why the average cost per unit of output is increasing, and the firm's profitability may be affected if it cannot find ways to reduce its costs.