Final answer:
The current market sizes of Sleekfon and Sturdyfon after their merger are 7 million units and 12 million units respectively.
Step-by-step explanation:
The current market sizes of Sleekfon and Sturdyfon after their merger are as follows:
- Sleekfon: 7 million units
- Sturdyfon: 12 million units
Therefore, the correct option is D. Sleekfon: 7 million units, Sturdyfon: 12 million units.