By the turn of the twenty-first century, had become the largest heavy industrial producer in the world.

Their underlying asset beta is closest to is 1.08

Explanation:

According to the given data we have the following:

Debt is given as $78 billion

Equity is given as $142 billion

equity beta given as 1.68

Therefore, in order to calculate the underlying asset beta we would have to use the formula of the the equity beta for a levered firm as follows:

betaE =beta A [1 + (Debt / Equity)]

1.68 = \beta A [1 + ($78 B/ $142 B)]

1.68 = \beta A [1 + 0.5493]

betaA = 1.68 / 1.5493

betaA = 1.08

Their underlying asset beta is closest to is 1.08