Upon the death of a spouse, one-half (½) of the aggregate value of the property owned by a community property trust established by the spouses reflects the share of the surviving spouse and the other one-half (½) reflects the share of the decedent. Unless provided otherwise in the trust agreement, the trustee has the power to distribute assets of the trust in divided or undivided interests and to adjust resulting differences in valuation. A distribution in kind may be made on the basis of a non pro rata division of the aggregate value of the trust assets, on the basis of a pro rata division of each individual asset, or by using both methods.