These are not structured answers. I'm just highlighting some important things you should consider:
(a) Consumers demanding cheaper products and employees wanting higher wages.
Here, the management skills of negotiation and problem solving are vital. Senior management must first settle the internal wage issues by negotiating with employee representatives or unions and come to an agreement regarding pay. During the negotiation process, senior management can mention the consumer demands for cheaper products and explain why increasing the wages by a substantial margin can affect the financial structure of the organisation. In regards to cheaper products, the business can compensate by finding a cheaper supplier to reduce the cost price of stock sold.
(b) Shareholders desiring a higher return on their investment and society wanting a clean environment.
Firstly, implementing environmentally friendly operations doesn't hinder a higher return on investment for shareholders. A higher ROI figure is achieved by increasing net profit. If a business markets itself as an environmentally friendly organisation, there is a high chance that it will attract more sales, given the fact that the society it operates in demands a clean environment. To reconcile this, the organisation should implement environmentally friendly practices.
(c) Managers being required to keep costs of production down and ethical suppliers wanting higher prices for inputs.
An organisation that fosters an ethical and socially responsible attitude towards business operations would not end its contract with the ethical suppliers and move on to illegal sweatshops or to suppliers that damage the environment. Again, senior management can negotiate with the suppliers and order its inputs in bulk, thereby reducing the input costs. Also, economies of scale should be implemented so that the cost price of a unit decreases. If the business couldn't care less about ethics, it can source its inputs form an unethical cheaper supplier.