Dear Mr. Lee,
I thank you and the management board for offering the post of Chief Accountant to me. However I have to decline for I would not be able to handle the additional responsibilities that come with the job.
As you know, my health has not been good recently and the doctor advised that I should take things easy. If things become worse, I might even have to go and have a hysterectomy done. So it is best that I do not take on any more burden than is necessary. You would not want your Chief Accountant to be in hospital for weeks, would you? That is a possibility if I take the job.
I suggest you offer the job to a younger and healthier person. My personal recommendation would be Ms. Tan. She is competent and reliable and I am sure she can do the job well. Thank you.