A. In the first iteration start with the definition of the Target Business Architecture using a Top down Approach.
Then keep on iterating in Phase B till the Target Business Architecture is refined before going to Phase C and Phase D.
After Phase C and Phase D are over, iterate again to Phase B and define the baseline Business Architecture, analyze the gaps finalize the Architecture Definitions documents and proceed to Phase C and Phase D.

B. In the first iteration start with the definition of the Baseline Business Architecture using a Top Down approach. Define the Architecture Definition document after analyzing the impacts and reviewing with the stakeholders. Then proceed to Phase C and Phase D.
In the next iteration finalize the Target Business Architecture and proceed to Phase C and Phase D.

C. In the first iteration start with the definition of the Target Business Architecture using a Top Down approach. Define the Architecture Definition document after analyzing the impacts and reviewing with the stakeholders proceed to Phase C and Phase D.
In the next iteration finalize the Baseline Business Architecture, determine the gaps and the roadmap, and the impact and update the Architecture Definition document. After analyzing the impacts and reviewing with the stakeholders. Then proceed with the iteration.

D. In the first iteration start with the definition of the Baseline Business Architecture using a Bottom Up approach. Define the Architecture Definition document after analyzing the impacts and reviewing with the stakeholders'.
Proceed to Phase C and Phase D.
In the next iteration finalize the Target Business Architecture, determine the gaps and the roadmap, and the impact and update the Architecture Definition document.
after analyzing the impacts and reviewing with the stakeholders. Then proceed with the iteration.