A.
I am asked to write a preface to this collection of his essays and I find it a great honor.
B.
I am able to write a preface to this collection of his essays and I feel it a great honor.
C.
Being able to write a preface to this collection of his essays, I feel greatly honored.
D.
I find it a great honor to be asked to write a preface to this collection of his essays.