I have a question about the meaning of these statements:
1a- The most effective method in developing and improving health is considered to be daily exercises. (Original)
1b- The most effective method developing and improving health is considered to be daily exercises.
1c- The most effective method to develop and improve health is considered to be daily exercises.
2a- He is wrong in saying, "Jack is stupid" . (Original)
2b- He is wrong saying, "Jack is stupid" .
2c- He is wrong to say, "Jack is stupid" .
Can I use the other versions instead of the 1a and 2a? Do 2b and 2c mean the same thing as the 2a version, and likewise with 1b and 1c?