4ExternalitiesMedium1 mark
The table shows the marginal costs and benefits of the last unit of output produced for four goods A, B, C and D.
| marginal private cost ($) | marginal external cost ($) | marginal private benefit ($) | marginal external benefit ($) | |
|---|---|---|---|---|
| A | 10 | 5 | 10 | 0 |
| B | 10 | 5 | 5 | 10 |
| C | 10 | 10 | 15 | 10 |
| D | 15 | 0 | 10 | 10 |
Which good is not causing market failure?