The correct answer is D. Has immature mental development.
A teacher with immature mental development may not be able to effectively teach students. They may have difficulty understanding complex concepts, and they may not be able to think critically or solve problems. They may also have difficulty managing their emotions, and they may not be able to relate to students in a positive way.
A teacher with physical disabilities may be able to teach effectively if they have the necessary accommodations. For example, a teacher who uses a wheelchair may need a classroom that is accessible, and they may need to use assistive technology to help them write on the board or grade papers.
A teacher from a low socio-economic status may have had fewer opportunities to learn and grow, but this does not mean that they cannot be an effective teacher. With the right support, teachers from low socio-economic backgrounds can be just as successful as teachers from other backgrounds.
A teacher with a weak personality may not be able to command the respect of their students, and they may not be able to motivate students to learn. They may also have difficulty dealing with difficult students.
Overall, a teacher with immature mental development is the most likely to have serious defects that will prevent them from being an effective teacher.